1. Field of the Invention:
This invention relates to an improvement of reinforcing layers such as breakers and the like for bias tires.
2. Prior Art:
In recent years, for large sized bias tires used on gravel and unimproved roads in mines, quarries and the like there have been used a breaker layer including at least one breaker ply which comprises composite cords made by twisting together aramid yarns and nylon fibers, instead of conventional steel cords as disclosed in the Japanese Patent Application laid-open No. 61-205501.
With the above breaker layer, when the treads impact on stones or hard objects in running, the breaker layer can diminish stresses impressed on the tread rubber and reduce damage to the tread. Said composite cords are free from corrosion and are hardly subjected to fibrillation and compression fatigue. Under more rough conditions, however, the conventional bias tires having such breaker layers are liable to be cut through by broken stones and the like which results in cord breakage and strength reduction of the breaker layer.